How do you quickly invite tens, dozens, hundreds of people to a party, rally, debate, play, show, election orsports event and keep them in the loop for time, location, theme updates? What tool do you use to maintain membership to a dozen groups, academic, social, or otherwise?
There's a lot of fluff to Facebook, but for certain use cases, it is untouched.
HardOCP had their custom heatsink with the thermo-probe for more reliable temperature measurement.
Techreport has been phenomenal over the years in this. They built a custom PSU tester to test the loads of any or all of the rails at once. Then they had their "inside the second" articles diving in to frame latency, which led to better Radeon drivers. More recently, and still running, is their SSD deep-cycle test, which is already showing blocks beginning to fail on SSDs.
The innovation factor and time taken to really dive in are things I don't see elsewhere.